The impact of much higher production combined with static demand during this fourth uranium age is substantial over-supply in the world uranium market, with prices naturally falling back to lower levels.nly part of the 2.5 million tonnes of uranium mined since 1945 has been utilised. Almost 2 million tonnes of depleted uranium is an attractive resource while there is overcapacity in enrichment and cheaper prices.
Inside the Torso. The body's functions are conducted by organs. Each organ is a recognizable structure (for example, the heart, lungs, liver, eyes, and stomach) that performs specific functions. An organ is made of several types of tissue and therefore several types of cells (see Cells). For example, the heart (see Heart) contains muscle tissue that contracts to pump blood, fibrous tissue that makes up the heart valves, and special cells that maintain the rate and rhythm of heartbeats.
The heart wall is composed of three layers. The middle layer, the myocardium, is responsible for the heartâs pumping action. Cardiac muscle, found only in the myocardium, contracts in response to signals from the cardiac conduction system to make the heart beat. Cardiac muscle is made from cells called cardiocytes. Like skeletal muscle cells cardiocytes have a striated appearance, but their overall structure is shorter and thicker.